To reduce the perceived effect of tinnitus, a tinnitus sound generator is often used to mask other sounds, but thereby reducing the listener's sensitivity to sources in the environment, to speech, or to other meaningful cues. Such masking could be lessened by attenuating the tinnitus sound as other sound sources appear. A system that first determined that a sound was present and only then began attenuating the tinnitus noise would react too late to affect masking of the stimulus onset, which frequently carries important identifying information for both speech and non-speech sounds. Thus, an early start to the attenuation of the level of the tinnitus sound has key potential advantages.
U.S. Pat. No. 5,325,872A describes a tinnitus masker with one or more signal generators, a controllable amplifier, one or two electroacoustic transducers for conversion of electrical signals into acoustic signals and a voltage source, whereby at least one of the signal generators generates a continuously repeated, sinusoidal pure tone signal which slowly moves through the audio frequency range and whose cycle duration can be adjusted between 0.1 and 1000 seconds.
U.S. Pat. No. 6,047,074A describes a digital hearing aid employable for tinnitus therapy, as well as for retraining tinnitus therapy, in combination with correction of other hearing impairments of a user of the hearing aid. The hearing aid contains a signal processing chain, between a hearing aid input and a hearing aid output, which is responsible for producing a useful signal by acting on the input signal in a manner to correct the hearing impairment of a user of the hearing aid. The signal processing chain also includes an arrangement for generating a tinnitus therapy signal, which is combined in the signal processing chain with the useful signal, dependent on a mode of operation which has been selected or set.
EP2533550A1 describes a listening device for a hearing impaired person being subjected to a tinnitus at a tinnitus frequency range. The listening device comprises a controllable filter for filtering an electric input signal such that a component of the electric input signal in the tinnitus frequency range is dampened if a detection signal indicates that the electric input signal is a broadband signal or left un-attenuated, if not.